now, malia recently got her first cell phone. do you monitor it? and see who she calls or who she texts? >> i give my daughter at this age, i give her a long rope. you know, and there is monitoring, because we have rules, but monitoring may be, you never know when i'm going to walk in your room and i'm going to definitely ask you, who are you talking to, are you talking about school work? >> and they're not very good at lying. we joke sometimes about how, you know, malia is getting to the age now, boys start calling and -- >> reporter: ah, yes. >> i always talk about how one of the main incentives for running again was continuing secret service protection. >> reporter: mr. president, mrs. obama, there is a photograph of you that went viral, became the most shared photograph in the history of twitter. how do you keep the fire going? >> hmm. that's a good question. >> you know, we've been married now 20 years.